A number of researchers are now convinced mothers seed their fetuses with microbes during pregnancy. They argue that this early inoculation may be important to the long-term health of babies. And manipulating these fetal microbes could open up new ways to treat medical conditions ranging from pre-term labor to allergies.

Many suspect that immune cells in the mother’s intestines swallow up bacteria there and ferry them into the bloodstream, where they eventually wind up in the uterus.

via Human Microbiome May Be Seeded Before Birth – NYTimes.com.